A standoff mooring bar for a vehicle such as a boat or a floating aircraft featuring an adjustable mooring bar body that is automatically locked at the desired mooring length when a guying rope and a mooring rope are tensioned. This body has an inner cylindrical tube telescoping within an outer cylindrical tube, and a pair of end caps closing the telescoping pair of tubes. The mooring rope extends through the pair of tubes by passing through openings located in both end caps. An automatic locking mechanism fixes the adjustable length of the telescoping pair of tubes when the tie ends of the mooring rope and guying rope are secured during mooring. When used in pairs on a craft, the guying ropes maintain the craft from moving forward or backward parallel to the docking structure; the locked telescoping tubes keep the craft from hitting and rubbing against the docking structure, or from moving away perpendicularly.